[R-390] Front Panel Restoration blasting trials CORRECTION

[Glenn Scott via R-390]

Cecil and anyone else not TOTALLY bored to tears with my post,


One correction; Aluminum Hardness is 2.5 to 3.0 not 4-5. Still, Sodium bicarbonate is only 2.5. The Aluminum on these panels is probably hardened and I defer that to the chemist in our group. However, after blasting MANY panels using Armex sodium bicarbonate I have seen no burrowing whatsoever. NONE, NADA, ZIP, ZILCH.. Just perfectly clean bare Aluminum panels ready to be processed. 


When I first started using Soda blasting years ago, I ended up blasting one particular panel 7 times due to a calamity of problems/errors from priming, painting and even waxing the final panel with a piece of debris on my buffing wheel. That swirled up the panel after everything I had done and back to the blasting equipment.. 


I was very mad and frustrated as I took that panel back for blasting for the 8th time. My wife was concerned that I was going to blow my head gasket. Hi   
However, everything came off quickly, AGAIN,, I repeated all of the steps listed in my ER article AGAIN and the engraves took paint and formed beautiful letters with ZERO indication of distortion or lack of fill. 
The science that I had investigated about hardness prevailed in spite of my ability to make LOTS of mistakes. 


I don't want to beat this point up too much but I honestly believe this is the best way to strip these panels that I am aware of. If someone  has a better method, I am listening. 


As mentioned, I MUCH prefer doing the electronics and squeezing every bit of performance out of these receivers as possible. I don't particularly like blasting, priming, painting nor waxing but I wear a lot of hats in my small business and some get dirtier than others...Hi  


73,
Glenn Scott WA4AOS
DSM Labs
glenn at dsmlabs.com



-----Original Message-----
From: Cecil <chacuff at cableone.net>
To: Glenn Scott <wa4aos at aol.com>
Cc: r-390 <r-390 at mailman.qth.net>
Sent: Sun, Jul 19, 2015 10:26 am
Subject: Re: [R-390] Front Panel Restoration Knobs Rock Tumbler


 
  
 
 
  
On Jul 18, 2015, at 9:45 PM, Glenn Scott via R-390 <  r-390 at mailman.qth.net>   
 
 
  
      
      
   Once the flow and pressure are dialed in, I can do one side of a panel in about 5 minutes or less with no subsequent picking of paint and primer from the engraves. The Armex powder pellets are small and get deep into into the engraves much better than anything else I have tried.  
 
 
  
 
 
 
  
   Strange..I use the HF blaster with their coarse media and it took me half an hour or more...a full bag of media ( maybe two..can't remember) and I killed the grass in a 20x20 area in the yard even after a good flushing with the hose. Humidity is a big deal with these things and during the summer her you can plan on 90% most days.I had frequent clogs and had to purge the system often..between those problems stripping was slow and used way more media than I had hoped.  That was my first try though...will have to have another go at it.  The glass bead blasting was very quick...wiped away the paint, primer, corrosion and cleaned out the engravings quickly...it was in a blast cabinet though and nicely contained.  
 
 
 
Cecil